Fluid liquid contacting device



All@ 2.4, 1954 L P. D. coPPocK 2,687,287

FLUID LIQUID coNTAcIING DDvIcE Filed June 8, 1351A INVENTOR PHI-LIP`DALTON COPPOCK,

ATTORNEYS Patented ug. 24, 1954 FLUID LIQUID CONTACTING DEVICE PhilipDalton Coppock, Epsom Downs, England,

assignor to The "Distill Edinburgh, Scotland, a

ers Company Limited,

British company Application June 8, 1951, Serial No. 230,666

Claims priority, application Great Britain June 8, 1950 Claims.

production of relatively coarse dispersions when large orifices areused, the necessity for high orifice velocities and consequent highpower consumption, wear and tear of moving parts and unsuitability forhigh pressure or corrosive conditions.

It has now been found that the difficulty associated with blockage ofthe ne apertures previously used for the dispersal of uids into liquidsby means of permeable diaphragms can greatly be reduced by means of adiaphragm having a multiplicity of apertures provided with closuremeans, actuated by the pressure differential across the diaphragm, toopen progressively with increase in the relative pressure of the uid tobe dispersed.

Accordingly, the present invention relates to a disperser comprising acontainer fitted with an air or fluid inlet means and covered with adiaphragm which consists of a sheet of a substantially rigid materialbearing one or more apertures wherein each aperture is provided withclosure means which open or close in response to variations in thepressure differential across the diaphragm. The closure means maypreferably be a rectangular flexible flap xed at one end and operativelybiased at the other end to remain closed in the absence of a suflicientdifferential pressure across the diaphragm and to providean inherentnon-return means by virtue of the overlap of its opposite biased edgewith respect to the aperture which it covers. Preferably the diaphragmbears at least 25 such apertures and bears at least one such apertureper square centimetre of diaphragm area. The present invention alsorelates to a process for the dispersion of fluids in liquids whichcomprises passing the fluid to be dispersed through a diaphragm as denedabove, immersed in the liquid.

The term aperture as used in the specification and claims is intended tomean any hole or orice made in the diaphragm by removal of diaphragmmaterial. It is preferred that the diameter of the apertures is in therange 116 inch to 1A, inch. The diaphragm may consist of a rigid plateof a metal such for example as steel, stainless steel, brass, copper,bronze, aluminum and aluminum alloys, or of a non-metallic material suchas Bakelite or other plastic materials, inert to the fluids in use.

It is preferred that the closure means should not incorporate anysliding mechanism such as the retaining means of mushroom or similarvalves. To prevent the liquid from flowing back to any substantialextent on reversal of the pressure differential, a non-return means mayad Vantageously be incorporated where this is not inherently present.The closure means prefer ably comprises a flexible flap or strip whichoverlies the aperture. The flexible flap is suitably made of a metal ofa thickness in the range 0.005 inch to 0.025 inch.

The accompanying diagrams illustrate various embodiments of theinvention.

Figure 1 is a diagrammatic plan View of a fragment of a diaphragm, andFigure 2 is a crosssection of Figure 1 along line X-X.

Figure 3 is a diagrammatic cross-sectional view of a disperser.

In Figures 1 and 2, the aperture A in the fragment B of the diaphragm isclosed by an overlaying strip CDEF of flexible material such as thinsteel plate secured to the diaphragm in the region of the edge CF. Onsupplying fluid under pressure the overlaying strip CDEF lifts slightlyto allow a thin stream to pass through and disintegrate into smallbubbles or globules in the liquid disposed on the other side of thediaphragm. Anumber of such apertures and closure means are provided onone diaphragm and should a substantial proportion become blocked bysolid matter, the resultant increased backpressure effects a wideropening of the closure means to allow the solid to pass through wherebythe diaphragm is self-cleaning. A non-return means is inherently presentby virtue of the overlap of strip CDEF with respect to aperture A.

The process and apparatus of this invention nd application generally forthe dispersion of a uid into an incompletely miscible or immiscibleliquid to give an intimate contact between the tworesulting phases, andmay be applied to the aeration of liquids, as in the aeration of fermenytation broths, and as in froth flotation processes, in gas washing bypassing the gas through a liquid, in the absorption of gases in liquids,in degassing liquids by blowing through an inert gas and in chemicalprocesses involving reacting a gas with a liquid, to vapour liquidcontacting,

as in distillation processes for the construction and operation ofbubble trays, and to liquidliquid contacting, as in solvent extractionprocesses.

The diaphragm is suitably mounted in a disperser comprising a containerI provided with a iiuid inlet l l, said diaphragm forming the fluidoutlet of the container, as shown in Figure 3.

I claim:

1. A disperser for the intimate dispersion of iluids into a liquidcomprising, a container, a diaphragm mounted on the top of saidcontainer, a fluid inlet means for the container, said diaphragm formingthe fluid outlet of the container and consisting of a substantiallyrigid sheet bearing at least one aperture per square centimeter ofdiaphragm area, each aperture: being provided with a rectangularflexible iiap Which opens and closes in response to variations in thepressure differential across the diaphragm, said iiap fixed at one endto the sheet and operatively biased for closure at the other end, andsaid nap having a cross sectional area substantially greater than thatof said aperture to thereby provide an inherent non-return means for theliquid int Which said disperser is immersed` 2. A disperser as in claim1 wherein said sheet bears at least 25 apertures.

3. A disperser as in claim 1 wherein said aperture is rectangular andthe short and long dimensions thereof are about 11;; inch and 1/4 inchrespectively.

4. A disperser as in claim 1 wherein said iiap is made of metal having athickness in the range of from about 0.005 inch to about 0.025 inch.

5. In a disperser adapted to be immersed into a liquid for the intimatedispersion of fluids into said liquid, formed of a container, adiaphragm mounted on the top of said container and a fluid inlet meansfor the container, said diaphragm consisting of a substantially rigidsheet bearing at least one aperture per square centimeter of diaphragmarea, each aperture being covered with an overlying rectangular flexibleilap which opens and closes in response to the pressure diiferentialacross the diaphragm, said flap xed at one end to said sheet andoperatively biased for closure at the other end, and said flap having across sectional area substantially greater than that of said aperture tothereby provide an inherent non-return means for the liquid and theoutletl means for the fluid Which is dispersed into the liquid.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 148,183 Crutchfield Mar. 3, 1874 249,557 Truesdell Nov. 15,1881 1,453,735 Twining May 1, 1923 1,759,983 Houston May 27, 1930

